Pinus spp.
Family: Pinaceae
Project: Southwest Biodiversity Consortium
Trees or shrubs aromatic, evergreen; crown usually conic when young, often rounded or flat-topped with age. Bark of older stems variously furrowed and plated, plates and/or ridges layered or scaly. Branches usually in pseudowhorls; shoots dimorphic with long shoots and short shoots; short shoots borne in close spirals from axils of scaly bracts and bearing fascicles of leaves (needles). Buds ovoid to cylindric, apex pointed (blunt), usually resinous. Leaves dimorphic, spirally arranged; foliage leaves (needles) (1--)2--5(--6) per fascicle, persisting 2--12 or more years, terete or ± 2--3-angled and rounded on abaxial surface, sessile, sheathed at base by 12--15 overlapping scale leaves, these (at least firmer basal ones) persisting for life of fascicle or shed after first season; resin canals 2 or more. Pollen cones in dense, spikelike cluster around base of current year's growth, mostly ovoid to cylindric-conic, tan to yellow, red, blue, or lavender. Seed cones maturing in 2(--3) years, shed early or variously persistent, pendent to ± erect, at maturity conic or cylindric, sessile or stalked, shedding seed soon after maturity or variously serotinous (not opening upon maturity but much later); scales persistent, woody or pliable, surface of exposed apical portion of each scale (apophysis) thickened, with umbo (exposed scale surface of young cone) represented by a scar (sometimes apiculate) or extended into a hook, spur, claw, or prickle; bracts included. Seeds winged or wingless; cotyledons (3--)6--10(--18). x =12.
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